What is the recommended management for a 10 mm fusiform splenic artery aneurysm?

Management of a 10 mm Fusiform Splenic Artery Aneurysm

Active intervention is recommended for a 10 mm fusiform splenic artery aneurysm, particularly through endovascular treatment such as embolization or stent grafting, as this represents the threshold size for increased rupture risk. While this aneurysm is at the borderline size for intervention, the evidence suggests that proactive management is warranted to prevent potentially life-threatening complications.

Risk Assessment and Natural History

• Splenic artery aneurysms (SAAs) are the most common visceral artery aneurysms, representing approximately 60% of all digestive artery aneurysms 1.
• The natural history of SAAs indicates that larger aneurysms have a higher risk of rupture, with a mortality rate of 10-25% in non-pregnant patients and up to 70% maternal mortality during pregnancy 2.
• Although the 10 mm size is at the lower threshold for intervention, evidence suggests that aneurysms ≥10 mm have a significantly higher annual rupture rate (approximately 1%/year) compared to those <10 mm (0.05%/year) 2.

Indications for Intervention

Intervention is recommended for SAAs with the following characteristics:

• Size ≥10 mm (current case) 3
• Symptomatic presentation 4
• Growth rate >0.5 cm/year 1
• Present in women of childbearing age 3
• Present in pregnant patients 2
• Present in patients following liver transplantation 4
• All false aneurysms (pseudoaneurysms) 4

Treatment Options

Endovascular Treatment (First-Line)

• Endovascular therapy is considered the primary therapeutic approach for SAAs due to its minimally invasive nature and lower morbidity and mortality compared to surgery 4, 1.
• Options include:
  • Coil embolization - most commonly used technique 1
  • Stent grafting - alternative approach for suitable anatomy 4
• Advantages include:
  • Lower perioperative morbidity 1
  • Better quality of life outcomes 1
  • More cost-effective strategy 1
  • Rarely associated with splenic infarction due to collateral circulation from short gastric vessels 1

Surgical Management (Second-Line)

• Reserved for cases with:
  • Ruptured aneurysms 1
  • Failed endovascular treatment 4
  • Anatomically unsuitable for endovascular approach 2
• Surgical options include:
  • Open ligation 3
  • Aneurysmectomy with or without splenectomy 5
  • Laparoscopic approaches in selected cases 1

Conservative Management

• May be considered for very small (<10 mm), asymptomatic aneurysms in low-risk patients 4.
• Requires regular imaging surveillance to monitor for growth 4.
• Beta-blockers may potentially have a protective effect against rupture based on limited evidence 3.

Follow-up Recommendations

• For patients undergoing endovascular treatment:

  • Post-procedure imaging at 1,6, and 12 months, then annually to assess for recanalization 1.
  • Monitor for post-embolization syndrome (pain, fever, systemic symptoms) 1.

• For patients managed conservatively (not recommended for this 10 mm aneurysm):

  • Regular imaging surveillance every 6-12 months to assess for growth 4.
  • Immediate intervention if the aneurysm becomes symptomatic or shows growth 3.

Special Considerations

• Calcification of the aneurysm does not appear to protect against rupture 3.
• Giant SAAs (>10 cm) are rare but carry significantly higher risk of complications including rupture and fistula formation to adjacent organs 5, 6.
• The fusiform shape may influence the technical approach to endovascular treatment but does not alter the fundamental recommendation for intervention at this size 4.